Chickens Flashcards
biggest producers of eggs
china
biggest exporters of eggs
America (north and south)
Main industry body for eggs in Aus
Eggs Australia (formerly known as Australian Egg Corporation)
Which of layers or broilers “vertically integrated”
Broilers are mostly vertically integrated while eggs are more likely horizontally integrated or independently owned.
How many registered layer farms in Aus
about 300
who are the main companies for egg production in Aus and where are they each based?
Pace: NSW,
Sunny Queen: QLD
Farm pride: VIc
Is there much export of eggs? why?
not really. only if there is an oversupply, they might be sold as processed product maybe.
Limitations to genetic improvement of Aus flock
You aren;t allowed to bring in any live animals into the country, only fertilised eggs that are hatched under strict quarantine conditions.
Industry is very structured in its grandparent, hatchery etc setup.
biggest broiler producers
Asia: mostly for internal consumption
biggest broiler export
USA and Brazil
What are the different levels of structure of the broiler industry:
Breeders: Fertilised eggs imported and become... Great grandparents Grand parents Parent Hatchery Broiler systems (all in-all out) Processing Retail.
ALso: feed mill and other inputs… in vertical integrationall of these levels are controlled by one company.
main broiler corporations:
70% of industry is Inghams or Baiada
other 30% is La Ionica and Hazeldenes
Ducks:
- main companies
- industry structure
- size of industry
- Pepes (restaurant), Luv a Duck (other)
- vertically integrated structure
- industry about $100 million, growing by 10% each year
Turkeys:
- main companies
- industry structure
- size of industry
- Baiada, Inghams
- vertically integrated
- not that popular except for seasonal demand in Aus= small industry
Is the genetic improvement of chickens fast or slow? why?
Rapid improvement due to short generational length, large numbers of offspring (can do heaps of sibling prog testing, can also select harshly).
Can select intensively for production traits as we dont need to worry so much about environmental resilience (controlled environements).
main 2 genetics companies:
EW and Cobb: they have a monopoly,… means its harder for others to get access to quarantine facilities (might not be able to import new genetics for years and so they fall behind).
outline quarantine process for bringing in new genetics
- fertilised eggs brought in
- hatched in quarantine for 6 weeks
- these become great-grandparents for different lines
Main broiler bird types:
Aviagen (Ross)
Baiada (Cobb)
Main layer bird types:
Hyaline, Lohmann (Hyline international Isa Brown (Baiada)
Why are heaps of lines maintained
Breeding stock of each pure line must be maintained as you cant store chicken semen.
They need to keep breeding them so the line still exists and can then be crossed with other lines when you want to make a hybrid.
brown eggs breeds:
- isa brown
- hyline brown
- Lohmann (new, meant to be designed for free-range but showing very odd behaviour so far)
Normal egg production for a layer hen
1 egg per day for about 90 weeks (about 400 eggs in lifetime)
what is acceptable mort rates for layers
less than 2%. Anymore than 1-2 birds per week in a shed would be well worth investigating
Key welfare issues for layers: (according to this lady)
Ethical: - off sex disposal, spent hen disposal Welfare: - beak trimming - cage housing - moulting (uncommon) - cage layer fatigue (nutritional, not really anymore) - feather pecking - cannabalism
Cage systems:
Positives:
- good social group size (5-6)= stable social order, less incidence of antisocial behaviour.
- strict legislation and auditing
- cage requirements (horizontal bars)
- lower mort rates
- better/easier disease control
- easier biosec
- increased control of nutrition, temp, ventilation, light.
- easier and cheaper management
- hygenic for birds, eggs, staff
Cage system: negatives:
- limited behaviour: walking, scratching, stretching, dustbathing, perching
- feather loss
- foot and leg problems
- cage layer fatigue
- cant escape aggressive behaviour
- hard to see bottom and top layers
What is a “colony” system? pros and cons
Colony is like an enriched bigger cage system with perches. Europe skipped this and went straight to aviary. Good: enrichment, bad: hard to manage
“nest box system”
Cages with nest boxes inside. Need to be taught to lay in boxes. unnecessary extra step.
Aviary sytem:
Common in Europe. Aus laws mean they need to be checked everyday, very difficult in this system. Limited in human access. Ventilation and temp still under full control.
Barn system: pros
- behavour expression possible
- improved bone strength (leg health)
- control of feed/water/environment still high
- automated egg collection possible
- easy to inspect birds
Barn system: cons
- disease and mort higher than in cage
- large gorup size= increase in anti-social behaviour due to social instability
- higher costs of prod and management
- dust and ammonia (vent issues)
- harder to depopulate/disinfect.
Winter/ summer garden:
great for extreme outdoor temp conditions but very hard to clean
Free range pros:
- best system for behaviour expression
- access to outdoors
- varied diet and environment
- automation possible for egg collection, feed/water in large, permanent set-ups (not in the mobile ones)
Free range cons:
- health: higher risk of disease and parasites
- welfare: predation or fear of pred
- lack of climate control (humidity, temp)
- higher cost of production (managment, space, food waste)
- hard to do on large scale
- environmental damage; pasture/soil degradation, nutrient overload
- increased use of chemicals to deal with other problems (potential for residues in product)
- food safety (dirty eggs)
- less biosecurity
Difficulty with the “range” in free-range
chickens quickly tear up the grass and decrease soil quality so they have to be moved. repasturing takes time!
Layer lifetime. What happens when?
0-21 days: hatching 0-16 weeks- rearing week 18: come into lay almost immediately week 19; early lay Lay goes until week 90 ish.
How much do layers eat per day?
about 100g of food. need to keep them on strict rations (checked regularly)
Key performance indicators for layers:
Egg weight: indicates feed intake, can compare flock performances.
Egg recovery: number of eggs laid- no. eggs removed (management)
Factors that can effect egg grading:
size, weight, colour/shell appearance, blood or poo or dirt on them, inclusions (e.g. chalazae, blood spots), albumen quality, yolk colour and uniformity, taste and odour, !!!!!production system type!!!!!
When should a hen come into lay?
ideal age, weight
At about 18-20 weeks. Ideal weight (about 1.5-1.9kg i think) is important because hens too skinny or fat can get metabolic problems later.
What happens to mortality rate as laying period progresses
will increase from 0% to about 7% at the absolute end of lay (90weeks). it should stay about 1-2% for most of the period though.
What happens to hen-day egg production % rate as laying period progresses
rapid increase from week 18-20. Peak from about week 23-35. Slowly declines from there (wont go below 50% until about week 50). At week 90 may be down to about 70%.
What happens to egg weight as laying period progresses
increases and peaks at about 60-70g at about week 27. Plateaus after this.
Main 2 types of broilers (genetic companies) in Aus:
how are they different?
Cobb and Ross. Cobb have chunkier legs (better leg health)
Key growth indicators for broilers:
- daily average growth
- FCR (1.6-1.8)- very high!
How big/how old are broilers when they’re eaten?
collection is at about 32-60 days (biggest ones collected first: partial depopulation of shed).
Dress-weight: 1.6-3.5 kg
Broiler BREEDER considerations:
- start laying quite late and are less productive than layers
- $$$ as they eat a shitload and dont lay much (selected for growth!)
Broiler breeder timeline:
Pullet rearing: week 0-19
Transfer to production (point of lay)
Production: Pre-lay (light stimulation) Onset of lay-week 23 Peak lay-week 29 End of lay-week 60-65 (taper off earlier than layers which go til week 90)
Broiler hatchery timeline:
Fertilised eggs sent here for incubation: Day 1: - sample eggs weighed and marked - eggs put in incubator (setter) - first flock fertility estimate done
Day 10-14:
- Candling
- early embryo mortality/egg fertility rates assessed
- egg weight loss assessed
Day 18-19:
- eggs moved from setter to hatcher
- infertile ones removed
- another egg weight loss check
Day 21:
- chicks hatch
- they all get sent to the growing facility in boxes of 100 to keep warm.
Specific conditions for placing new chicks in broiler shed:
Air temp: 30-32C
Floor temp: 28-30 (** important as they lose heat through their feet)
Humidity: 60-70%
Can either do “whole shed” or “half shed” brooding. Half can be better for management and ensuring everyone is accessing food and water
Effect of temperature on broiler production:
- minimal diurnal variation is best.
- warm= eat less
- cool= eat more but too cold= increased maintenance metabolic rate (less FCR)
Optimum is about 21C
After chicks are a bit bigger should reduce humidity and heat to keep the litter dry
Effect of litter type/quality on broiler production:
can effect flock health due to:
- ammonia (can be bad by the time pick up happens)
- dust (turning increases this)
- disease (faeces and urine in litter> parasite load, coccidia etc)
Wet litter is really bad!
Effect of feed distribution on broiler production:
Short period, frequent feed: - less waste - maximises intake Feed deprivation (too long between); - less FCR - poor flock uniformity (smaller ones miss out and fall behind)
Effect of stockperson stress on broiler production:
Fear of humans, flight response to stockpeople can =
- less FCR
- increased mortality (stress on already struggling cardio-resp system)
Effect of overall flock health on broiler production:
- disease= higher maintenance metab= less FCR
- disease= less flock uniformity
Peak growth:
growth will peak about day 35. will taper off about 42. most are picked up around this point anyway.
Phase feeding timeline for broilers:
Starter feed: 0-14 days (high protein= 25%, lower CHO= 13MJME)
Grower feed: 14-16 days (less protein than starter)
Finisher feed (there will be finisher 1 and 2): 25-processing (less protein, slightly more CHO than starter)
Withdrawal: birds older than 42 days (hardly any would make it to this)
what are the 2 types of fertility testing in a broiler hatchery?
Day 1: pre-incubation, a sample (360/1000) is broken open to check for fertilisation.
Day 10-14 of incubation: candling of eggs in the incubator (remove those that arent fert)
When are broilers fully feathered?
day 25: need extra heat until this point
Why is wet litter bad?
- foot bad lesions
- less growth
- better enviro for disease to dwell
- breast blisters
- increases ammonia levels= resp disease
Waht is ideal moisture content for litter?
20-25%, should be friable but not too dusty.
Important parameters for adequate ventilation:
- dust <8mg/m3
- ammonia <25ppm
poor vent= bad litter, poor carcass weight, quality, yield, FCR, bird health.
Average flock size for broilers
20-80 thousand per shed
housing systems:
cage (not in Aus)
barn (full or partially/naturally ventilated)
Free-range: barn + range
Barn pros
- auto control of environment
- rapid, efficient growth
- minimal waste
- no predation
Barn cons
- no outdor access
- litter can get wet- foot scald, breast blisters
- resp disease; high ammonia is a big issue
free range pros
- free to go out or come in during day
- range= exercise good for leg health
- nerichment and natural behaviours
- lower stocking density
- it makes us feel slightly better
free-range cons
- birds stay inside for 1st 25days anyway (until feathered)
- need to provide shelter
- no feed or water outside = less intake= less growth
- need to manage range (ground cover, parasite load, nutrient overload etc)
- they dont use the ranges that much atm
- breeds inappropriate for this system
- predation and biosec
- increased flock variation
- inefficient use of space ($$)
Transport requirements:
max time off feed is 10-12 hours. (need to be close to processing palce)
- off food for a little while to “empty out” = less carcas contamination.
What are the steps of broiler slaughter/processing?
Primary:
- bird stunning- gas or electrical
- scalding/plucking- water/steam
- Evisceration
- Chilling- water/air
Secondary:
carcass processing
Stunning requirements:
50-60hz + water
or just 300hz
full immersion or just head/neck.
Gas (controlled atmosphere): single stage: argon, CO2 or N Two stage; -O2 + Co2 -C02
Which stunning method is better welfare? why?
Controlled atmosphere stunning is better:
Welfare (birds):
- not hung up while conscious
- less stress pre-slaughter
- no chance of birds entering scald area still alive
Welfare (Human):
- better conditions (lighting, safety, handling etc)
CArcass qual:
- better yeild
- less stress= better meat
- less broken bones and blood spots as they are not hung up this way
What is candling?
light is passed through the egg to see if there is a viable embryo inside: performed at day 10-14 of incubation at hatcheries
*dead embryos are called “clear”
How is the “donor flock” fertility measured for a hatchery
Fresh egg breakout in first 7-14 days
What is fresh egg breakout?
Pros, cons
The eggs are broken and the germinal disc is examined to see if fertile or not.
For every thousand a sample of 360 is taken.
Pro: fert can be measured on day of lay.
Con: cant measure embryo mortality, contamination or other post-lay issues this way.
how can you tell if a germinal disc is fertile?
Infertile blastodisc: small round spot
Fertile: bigger white circle
Possible causes of decreased fertility of donor flock
- poor genetics (unlikely considering how much work goes into breeding lines)
- nutrition
- too few roosters for no of hens
- high stocking density
- disease
- overuse of rooster (breakdown)
- temperature
- increasing age of flock
Estimated hatchability
Hatchaility
Estimated; uses data from breakouts and candling to estimate how many chicks willl hatch on a day
Actual: on day of hatch… used to assess performance of each donor flock.
Can compare 2 donors performance in same hatching conditions.
Comparison will tell you if it is the donor flock or the hatchery causing a problem
Donor flock performance peaks and measures:
Fertility, hatchability and hatch of fertiles all peak around week 40 of life and steady decline until end of lay (65)
What environemental factor effects egg water loss:
humidity.
What is normal egg weight loss?
11-12% between lay and 18 day transfer from setter
What is hatchday breakout?
Any eggs that dont hatch on the right day are broken and analysed for the reason they didnt hatch
Possible causes of repro failure:
- embryo malposition
- infertility
- embryo mort (week 1, 2, 3),
- embryo abnormalities
- pipped but unhatched (not strong enough to get out)
- cull eggs
- cracks
- contaminated eggs (rots, bangers)
- cull chicks
- upside down eggs
What does chick yield tell us
whether the conditions and timing of the incubation and hatch are correct.
It is a measure of how much the chick weighs at hatch as a percentage of how much the egg weighed at the beginning.
**chicks weigh less than eggs
if you require 250000 chicks to hatch on a certain day to maintain your numbers and %hatchability is 87% then how many eggs do you need to put in the setter?
no eggs to set= no chicks req/(%hatchability/100)
eggs= 250000/ (87/100) eggs= 287356
Why use hatchability to calculate how many eggs you need rather than fertility?
Fert doesnt take into account the eggs not hatching for other reasons. not all fertile eggs will hatch= you may underestimate how many you need
Why do you need multiple donor flocks of different ages?
If you only had an old supplying you with eggs for your hatchery you would need a lot more eggs to supply your day old chicks than if a younger flock supplied eggs. This is why a number of flocks of varying ages are used to provide a continuous supply of eggs to the hatchery. This ensures that the good flocks balance out the bad flocks as they start and finish production, ensuring the hatchery maximizes production and minimizes waste.
